Patent Document 1 describes, as a process for providing a graphite film having excellent electrical conductivity and thermal conductivity, “a process for producing a graphite film and fiber comprising graphitizing at least one polymer film or fiber selected from polyoxadiazole, polybenzothiazole, polybenzobisthiazole, polybenzoxazole, polybenzobisoxazole and polythiazole by thermally treating the polymer film or fiber at a temperature of 400 to 700° C. under vacuum or in an inert gas with tension applied thereto and then thermally treating the polymer film or fiber at a temperature of 1,600° C. or more under vacuum or in an inert gas”, which is a so-called polymer pyrolysis process. Patent Document 2 also describes a so-called polymer pyrolysis process.
Patent Document 3 describes “a process for producing a graphite comprising thermally treating aromatic polyimide at a temperature of 2,200° C. or more and pressure bonding the resulting multiple carbonaceous films in a temperature region of 1,600° C. or more with a pressure of 4 kg/cm2 or more applied to the films”.
A process for producing a graphite comprising burning a kneaded product made of carbon raw material powder such as coke and a caking additive such as tar pitch and then electrically heating the burned product (Patent Document 4) is known as a process for producing a large quantity and volume of a graphite having inferior electrical conductivity and thermal conductivity but used for a bearing, seal, crucible, heating element or the like with high productivity.
Further, a process for producing a film-like graphite comprising thermally treating at a temperature of 2,400° C. or more a polymer film having a thickness enough to provide a graphite film by generation of gas from the film by heating at normal pressure; and rolling the resulting graphite film (Patent Document 2) is known as a process for producing an excellent film-like graphite having high flexibility and toughness.    Patent Document 1: Japanese Patent Laid-Open No. 61-275116    Patent Document 2: Japanese Patent No. 2976481    Patent Document 3: Japanese Patent Laid-Open No. 64-56364    Patent Document 4: Japanese Patent Laid-Open No. 5-78111